Installation

Read this first

Flashing the wrong boot image can leave the phone unable to boot. Always keep the stock image of the exact ROM you are running so you can flash it back, and back up your data first.

Before you start

• An unlocked bootloader.
• Android Platform Tools (adb, fastboot) on your computer.
• The stock init_boot image (phones that launched with Android 13+) or boot image (older phones) from the firmware of the exact ROM you are running.
• The latest SU Kernel app from the Download page.

Check your KMI

adb shell uname -r

Output like 5.15.148-android13-8-... means KMI android13-5.15. You rarely need it: the app picks the right kernel module when it patches.

First install: patch the boot image

1. Install the SU Kernel APK and open it.
2. On the home screen tap Tap to install, then Select a file and patch.
3. Pick the init_boot.img (or boot.img) you copied to the phone.
4. Apps to grant root opens. SU Kernel is always included; add other apps that should have root on the first boot.
5. Optional: Block kernel modules stops some kernel modules from loading at boot (for example a vendor anti-root module). The app pre-fills suspicious loaded modules; edit or clear them.
6. Tap Next. The app writes camsu_patched_<date>_<time>.img to your Download folder.
7. Copy it to the computer, reboot the phone to fastboot and flash:

adb reboot bootloader
fastboot flash init_boot camsu_patched_xxx.img   # older phones: fastboot flash boot ...
fastboot reboot

8. After boot, open SU Kernel once. It installs /data/adb/camd the first time; until then other apps cannot call su.

Patching on a computer

camd for Windows, Linux and macOS is on the Download page:

camd boot-patch -b init_boot.img --kmi android14-6.1

The patched image lands in the current folder. SU Kernel still gets root because the kernel always roots the cam.su.kernel package signed with the official key.

Already rooted: direct install

When the phone is already rooted (LKM update, or moving from another root method), choose Direct install (Recommended): the app patches the current image and flashes it, no computer needed.

• Before flashing, the app disables every enabled module so the first boot on the new version is clean. If disabling one fails, it stops and does not flash.
• On phones with a self-signed AVB key (avbroot, yellow state) both direct options are hidden: an image patched on the phone is not signed and a locked bootloader would refuse it.

After an OTA update

An OTA writes the new system to the inactive slot, without root. Once the OTA has installed (before rebooting), open SU Kernel and choose Install to inactive slot (After OTA), then reboot.

Updating the app and the kernel module

• The app checks for releases every 12 hours, notifies you, verifies the signature and installs with root.
• The reinstall LKM button on the home screen only shows when the kernel part actually changed. No button, no reflash.

Uninstall or recover

• Module bootloop: after 3 failed boots in a row camd disables the newest modules (Features tab). If it fails before post-fs-data, use safe mode (hold a volume key while booting).
• Go back: each flash keeps the previous image in /data/adb/cam/previous/<partition>.img. For the first install use your stock image:

fastboot flash init_boot init_boot.img

• Remove completely: flash the stock image and uninstall SU Kernel.